1. Field of the Invention
The present invention relates to systems and methods for improving sleep quality, and, more particularly, to systems and methods for electronically receiving and evaluating inputs related to people suffering from sleep disorders.
2. Description of the Related Art
More than forty million people living in the U.S. suffer from chronic, long-term sleep disorders. Because quality of sleep plays a major role in cognitive, physical and emotional well-being, these disorders have a significant negative effect on the quality of life of these individuals.
Sleep disorders are known to burden the U.S. health care system with approximately sixteen billion dollars in direct annual medical costs. The most prevalent sleep disorders are sleep apnea and insomnia. According to the National Institute of Health, about one in nine Americans suffer from sleep apnea, and about one in eight Americans suffer from chronic insomnia. If left untreated, subjects with chronic insomnia may experience the symptoms of their sleep disorder for decades, typically starting in young adulthood.
Chronic insomnia imposes a high burden on the health care system due to its high prevalence in the general population. There is little reliable data about the indirect costs that are caused by the increased number of accidents and reduced productivity due to chronic sleep disorders, but studies have shown that subjects suffering from undiagnosed insomnia spend approximately $1,000 more per person per year in direct medical expenses than do healthy subjects.
Subjects suffering from insomnia experience difficulty in initiating sleep, difficulty in maintaining sleep, or they wake up too early and find it difficult to go back to sleep. For a clinical diagnosis of insomnia, at least one of the above symptoms needs to be present. In addition, the symptoms or a combination of them must result in non-restorative or poor quality of sleep. Insomnia is classified as chronic if it persists for at least thirty days.
Chronic insomnia can be caused by substance abuse, mental disorders such as depression, breathing disorders, or by other sleep disorders such as periodic limb movement. Chronic insomnia can also be caused by the subject's life style and environmental factors resulting in poor sleep hygiene. Subjects are deemed to have poor sleep hygiene if they consume beverages with alcohol or caffeine, eat large meals, or engage in physically or mentally stimulating activity shortly before bed time. A highly variable bed time, or inadequate temperature, poor ventilation, noise or light within the sleep environment are also known to impact sleep hygiene negatively. Insomnia can also be a disease in itself, in which case it is not caused by another physical or mental condition.
For the diagnosis of a number of sleep disorders, polysomnography has become the gold standard. Polysomnography is a diagnostic procedure in a specially equipped laboratory or in a patient's home. During this procedure, numerous sensors are attached to the patient's body, and data is recorded for several hours or even for a whole night. The recorded data is interpreted by a sleep specialist. This provides the basis for the diagnosis of sleep disorders such as sleep apnea. Sleep apnea is a sleep disorder which is characterized by irregular breathing patterns while subjects are asleep. Among the typical sensor data acquired during polysomnography are: electroencephalogram, electro-oculogram, electromyogram at chin and tibalis, oxygen saturation, nasal and oral air flow, snoring via tracheal microphone, body position via gravity sensor, and abdominal and thoracic respiratory effort via induction plethysmography.
Unlike in the diagnosis of sleep apnea, polysomnography is not a standard instrument in the diagnosis of insomnia, and it is not indicated as a standard measure for therapy outcomes either. Only if sleep related breathing or periodic limb movement is suspected as the cause for insomnia, or if the previous treatment has failed, is polysomnographic evaluation in a sleep laboratory recommended. This is due to the high variability of sleep duration, sleep onset, and awakening in patients suffering from insomnia. Another factor is first night effects that cause some insomnia patients to sleep worse in a novel sleep environment, but patients suffering from psychophysiological insomnia typically sleep better on their first night in the laboratory than they do at home. Common tools for the diagnosis of insomnia are self-reports, questionnaires, and sleep logs. Detailed questionnaires for the diagnosis of sleep disorders, such as the Pittsburgh Sleep Quality Index, have been developed, but clinical practitioners typically rely on less information and often require patients to record only the time they went to bed, the time they fell asleep, and the number of times they woke up during the night until the time they got up, at least one week prior to the first consultation.
Nowadays, clinicians depend on the patient's description of their symptoms. In the diagnosis of insomnia, patient self-reports concerning sleep quality play an important role. As sleep onset occurs unconsciously, there exists an intrinsic problem with the inaccuracy of self-reports concerning sleep quality. Patients tend to overestimate the lengths of time they are awake, and they generally underestimate the lengths of time they are asleep. Even though these reports are known to be inaccurate, they remain the basis for the diagnosis of insomnia to this day.
Clinicians also use reports of bed partners to determine whether or not certain sleep disorder symptoms are present that the patient may not be aware of Examples for these disorders are periodic limb movements or co-morbid sleep breathing disorders. For certain groups of the population, however, these reports cannot be obtained. Clinicians cannot get self-reports from infants or subjects with cognitive or mental disorders, such as dementia patients. For children, teenagers, young adults, singles, or seniors, a bed partner may not exist from whom to get information. In the evaluation of sleep hygiene, it is also important to determine to what extent environmental factors or personal habits negatively impact a patient's sleep quality. Examples of environmental factors causing poor sleep hygiene are improper ventilation, improper temperature, bright lighting, and high noise levels. Eliciting this information from patients during interviews poses additional challenges for clinicians.
The current options available for treatment of insomnia are pharmacological treatment, and cognitive behavior therapy. Pharmacologic treatment is the option most commonly chosen, even though it is known to have questionable long-term efficacy and it is associated with numerous side effects. Side effects of pharmacologic sleeping aids include memory impairments, altered sleep structure, risk of physical and psychological dependence, increased risk of falling and hip fracture for geriatric patients, and elevated risk of road accidents for elderly drivers. In addition, subjects suffering from a sleep breathing disorder and co-morbid insomnia must not take pharmacologic sleeping aids as they can prevent them from awakening enough to breathe. Thus, even though the symptoms of their sleep breathing disorder can be treated, these subjects will continue to suffer from their insomnia symptoms.
Non-pharmacological treatment, e.g., cognitive behavior treatment for insomnia (CBT) or psychotherapy, has been shown to improve quality of sleep in insomnia patients, and it achieves better long-term sleep improvements than pharmacological treatment. A typical CBT program combines education regarding sleep hygiene, stimulus control therapy, sleep restriction therapy, relaxation training, and cognitive therapy. Education regarding sleep hygiene teaches the patient how to avoid the factors mentioned above that can impact sleep quality negatively. Sleep restriction therapy is based on allotting a fixed time slot for lying in bed. The patient is prescribed to try to sleep only during this time period. Thus, the patient develops the habit of making more efficient use of the time in bed for sleep. Relaxation therapy is governed by light physical exercises that reduce tension in certain muscle groups, and training that reduces cognitive arousals. Finally, cognitive therapy corrects patients' misperceptions and fears regarding their need for sleep. Often insomniacs obsess about not being able to fall asleep, which raises tension and exacerbates insomnia. Administration of CBT typically takes eight weeks and up to ten therapist sessions of ninety minutes. Treatment cost due to required clinician time and availability of specialists experienced in CBT treatment inhibits widespread use of this non-pharmacological treatment option. CBT can reduce the severity of insomnia symptoms significantly, but demanding life events and bereavement may cause symptom relapse. For this reason, booster sessions of CBT are needed to help patients cope with relapse of symptoms especially in times of physical or psychological distress. Current therapy regimen, however, provide no means for intervention when patients are at risk for relapse or when their compliance declines.
Most subjects suffering from insomnia discuss the symptoms of their sleep disorder with their primary car physician (PCP) first. The PCP can prescribe pharmacological sleeping aids if other health problems can be excluded. Otherwise, the PCP may refer the patient to a sleep specialist who will require the patient to fill out a sleep diary and questionnaires before the first consultation. The questionnaires are used to screen for physical and mental health problems. In the sleep diary, the patient is supposed to log times of going to bed, times of awakening during the night and in the morning, and times of rising. Most specialists also require patients to log their intake of medication and other substances such as alcoholic or caffeinated beverages. Most commonly, sleep aids are prescribed if the sleep specialist can exclude other sleep disorders, e.g., sleep breathing disorders and mental disorders. The patient's self-reports consisting of the filled out questionnaires and sleep diaries are the basis of the specialist's evaluation, but a sleep study may be required to gain certainty as to the absence of other sleep disorders.
What is neither disclosed nor suggested in the art is a system and method for monitoring, assessing and improving a patient's sleep quality that overcomes the problems and limitations described above.